Denisova DNA proof of parenting

An article on the BBC by Helen Briggs - Cave girl was half Neanderthal, half Denisovan - reports on the DNA research emerging from a cave in Russia.

Site of the Denisova cave in Siberia (left. Image: B VIOLA, MPI-EVA) and the cave entrance.

According to researchers, some 50,000 years ago the pairing of two types of humans resulted in a daughter. DNA extracted from bone fragments found in the cave show the girl was the offspring of a Neanderthal mother and a Denisovan father. The discovery has been reported in Nature.

Viviane Slon, researcher at the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig, Germany, states that previous studies have pointed to the fact that Neanderthals and Denisovans (humans like us, but belonging to different species) must have occasionally had children together, but finding an actual offspring of the two groups was very lucky - all of this coming from a single fragment of bone found in the Denisova cave by Russian archaeologists several years ago. Bence Viola of the University of Toronto states that the fragment is part of a long bone, and from that they could estimate that the individual was at least 13 years old.

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Is everyone part Neanderthal? Present-day, non-African humans have a small proportion of their DNA that comes from Neanderthals. Some other non-African populations, depending on where they live, also have a fraction of their DNA that comes from an Asian people known as Denisovans. The fact the genes have been passed down the generations shows that interbreeding must have happened.

Excavations at the cave. Images: B VIOLA, MPI-EVA.

Archaeologically, however, the only known site where fossil evidence of both Denisovans and Neanderthals has been found is at Denisova cave in the Altai Mountains of Siberia. And very few archaic humans (those belonging to species other than our own - Homo sapiens) have had their genomes sequenced.

Neanderthals and Denisovans are known to have overlapped in time in Eurasia. The two groups lived until about 40,000 years ago; Neanderthals in the west and Denisovans in the east. As Neanderthals migrated eastwards, they may have encountered Denisovans at times, as well as early modern humans.

Svante Pääbo, director of MPI-EVA states that Neanderthals and Denisovans may not have had many opportunities to meet, but when they did they must have mated frequently - much more so than previously thought.